Processes and structures for IC fabrication

1. A method for fabricating an integrated circuit, the integrated circuit comprising an analog function and a digital function, the method comprising:

separating the integrated circuit into an analog portion and a digital portion, the analog portion comprising:

passive components within the integrated circuit, the passive components utilizing dielectric materials different than silicon dioxide; and

active components within the integrated circuit, the active components utilizing channel materials different than substrate single crystal silicon; and

fabricating the analog and digital portions in separate wafers in separate analog and digital fabrication facilities, wherein the analog and digital portions comprise bond pads for I/O connections.

2. A method as in claim 1 wherein the analog portion further comprises at least one of

components not commonly processed in a digital fabrication facility;

components having materials not available in a digital fabrication facility;

components having critical dimensions 5× greater than the critical dimension of a digital fabrication facility;

active components constructed in non-CMOS processes; and

components to minimize the chip area of the digital portion.

3. A method as in claim 1 wherein the passive components comprise a capacitor structure with a dielectric constant greater than that of silicon dioxide.

4. A method as in claim 1 wherein the active components comprise thin film transistors.

5. A method as in claim 1 further comprising

assembling the analog and digital portions to form the complete integrated circuit, wherein the assembling comprise bonding corresponding bond pads between the analog and digital portions.

6. A method as in claim 1 further comprising

placing the analog and digital portions in an at least partially stacked configuration.

7. A method as in claim 1 further comprising

placing the analog and digital portions in an at least partially coplanar configuration.

8. A method as in claim 1 wherein the integrated circuit comprises an RFID circuit.

9. A method for fabricating an RFID circuit, the method comprising:

separating the RFID circuit into an analog portion and a digital portion, the analog portion comprising a capacitor utilizing dielectric material having dielectric constant greater than that of silicon dioxide; and

fabricating the analog and digital portions in separate wafers in separate analog and digital fabrication facilities, wherein the analog and digital portions comprise bond pads for I/O connections.

10. A method as in claim 9 further comprising

assembling the analog and digital portions to form the complete integrated circuit, wherein the assembling comprise bonding corresponding bond pads between the analog and digital portions.

11. A method as in claim 9 further comprising

placing the analog and digital portions in an at least partially stacked configuration.

12. A method as in claim 9 further comprising

placing the analog and digital portions in an at least partially coplanar configuration.

13. A method for fabricating an RFID circuit, the method comprising:

separating the RFID circuit into an analog portion and a digital portion, the analog portion comprising a transistor having polysilicon or printed single crystal silicon channel; and

fabricating the analog and digital portions in separate wafers in separate analog and digital fabrication facilities, wherein the analog and digital portions comprise bond pads for I/O connections.

14. A method as in claim 13 wherein the analog portion further comprises thin film transistors.

15. A method as in claim 13 further comprising

assembling the analog and digital portions to form the complete integrated circuit, wherein the assembling comprise bonding corresponding bond pads between the analog and digital portions.

16. A method as in claim 13 further comprising

placing the analog and digital portions in an at least partially stacked configuration.

17. A method as in claim 13 further comprising

placing the analog and digital portions in an at least partially coplanar configuration.

18. A method for fabricating an integrated circuit, the integrated circuit comprising an analog function and a digital function, the method comprising:

separating the integrated circuit into an analog portion and a digital portion, the analog portion comprising:

passive components within the integrated circuit, the passive components utilizing dielectric materials different than silicon dioxide; and

active components within the integrated circuit, the active components utilizing channel materials different than substrate single crystal silicon; and

fabricating the analog and digital portions in separate wafers in separate analog and digital fabrication facilities, wherein the analog and digital portions comprise bond pads for I/O connections;

assembling the analog and digital portions in wafer form to form the complete integrated circuit, wherein the assembling comprise bonding corresponding I/O connections between the analog and digital portions.

19. A method as in claim 18 further comprising

placing the analog and digital portions on top of each other so that the bond pads on one portion line up with bond pads on another.

20. A method as in claim 19 further comprising

placing the upper portion faced up;

forming electrical contacts through the interconnect vias.

21. A method as in claim 18 further comprising

forming electrical contacts between the bond pads by flip chip packaging.

22. A method as in claim 18 wherein assembling in wafer form comprises a transfer printing utilizing thermal decomposable adhesive.

23. A method as in claim 18 further comprising

packaging the complete integrated circuit.

24. A method for fabricating an RFID circuit, the method comprising:

separating the RFID circuit into an analog portion and a digital portion, the analog portion comprising at least one of a capacitor utilizing dielectric material having dielectric constant greater than that of silicon dioxide, and a transistor having polysilicon or printed single crystal silicon channel; and

fabricating the analog and digital portions in separate wafers in separate analog and digital fabrication facilities, wherein the analog and digital portions comprise bond pads for I/O connections;

assembling the analog and digital portions in wafer form to form the complete integrated circuit, wherein the assembling comprise bonding corresponding I/O connections between the analog and digital portions.

25. A method as in claim 24 further comprising

placing the analog and digital portions on top of each other so that the bond pads on one portion line up with bond pads on another.

26. A method as in claim 25 further comprising

placing the upper portion faced up;

forming electrical contacts through the interconnect vias.

27. A method as in claim 24 further comprising

forming electrical contacts between the bond pads by flip chip packaging.

28. A method as in claim 24 wherein assembling in wafer form comprises a transfer printing utilizing thermal decomposable adhesive.

29. A method for fabricating an RFID circuit, the method comprising:

separating the RFID circuit into a digital logic portion, a memory portion, and an rf portion; and

fabricating the digital logic, memory, and rf portions in separate wafers in separate fabrication facilities, wherein the analog and digital portions comprise bond pads for I/O connections;

assembling the analog and digital portions in wafer form to form the complete integrated circuit, wherein the assembling comprise bonding corresponding I/O connections between the analog and digital portions.

30. A method as in claim 29 further comprising

forming electrical contacts between the bond pads by flip chip packaging.

31. A method as in claim 29 further comprising

placing the analog and digital portions on top of each other so that the bond pads on one portion line up with bond pads on another.

32. A method as in claim 29 wherein assembling in wafer form comprises a transfer printing utilizing thermal decomposable adhesive.